1. The Field of the Invention
The present invention relates generally to the field of breathable air storage vessels. More particularly, it concerns a miniaturized lightweight air pressure vessel for use as a portable source of breathable air.
2. The Background Art
Portable breathable air tanks are known in the art for use in activities such as scuba diving and fire fighting. Tanks have been built which are strong enough to withstand pressures in the range of 2,000 psi to 3,000 and which are light enough to be carried strapped to the user's back. The conventional breathable air tanks known to applicants are made of cast steel or aluminum.
However, the conventional breathable air tanks are characterized by a number of disadvantages. The strength of the metal used in the tanks requires a tank to be larger and heavier in order to withstand the pressures in the 3,000 psi range. The larger and heavier the tank, the more breathable air it can hold and the higher failure strength it has but the more difficult it is for the user to maneuver. The competing needs of size, strength and maneuverability require a judgment call in optimizing the design. The conventional tank which weighs about thirty-five pounds and holds about thirty-five to forty minutes worth of breathable air, and tends to have a safe use limit of about 3,000 cycles of air. The conventional tanks are so heavy that only two tanks can be safely worn by one person at a time. Although smaller vessels made of stronger metal have been developed for storing industrial gases and the like, no such tanks have been developed for storing breathable air. Of current interest are portable tanks for containing breathable air which are smaller, lighter and capable of holding more air at higher pressures.